The present invention relates in general to a continuously powered mainstore for large memory subsystems, which increases the effective lifetime of a battery backup system, when running in a battery backup mode. More particularly, the present invention relates to a memory arrangement, where the memory control logic which drives a memory array, is maintained in a volatile power domain, and clock redrive circuitry, address control redrive drive circuitry, data transceivers, and the memory array itself all are maintained in a non-volatile power domain. Such an arrangement reduces the power consumption of the entire computer system and significantly increases the effective lifetime of the battery backup system.